I've been trying to determine if I have the correct oil pressure sender on my 289 (the motor is 1968...car 1967). I've searched this site with no results (maybe it's just me ) . I've browsed several vendor's websites and got conflicting info. There are two types, the SW667 "shorty" style and the larger SW673. One site says the 673 style is for 67-68 cougar 289 with tach and in the same line 67-69 Mustang 289 without tach??? Another site indicates the 673 is for a cougar with tach. Should there be a difference between Cougars and Mustangs??? Then another site indicates the 667 "shorty"style is for 67-68 Cougars with a 289. Can anyone tell me which one to use on a 68 289 in a 67 coug with NO tach, just the warning light?